Hypoglycemic agents

ABSTRACT

Provided is a method for treating hyperglycemia utilizing certain rhodanine derivatives. Certain of the rhodanine derivatives utilized in the instant method are novel and, accordingly, such compounds and pharmaceutical formulations thereof, are also provided.

This application is a continuation of application Ser. No. 08/343/271 filed Nov. 22, 1994, now abandoned which is a continuation of application Ser. No. 07/943,353 filed Sep. 10, 1992, now abandoned.

BACKGROUND OF THE INVENTION

Diabetes mellitus is a systemic disease characterized by disorders in the metabolism of insulin, carbohydrates, fats and proteins, and in the structure and function of blood vessels. The primary symptom of acute diabetes is hyperglycemia, often accompanied by glucosuria, the presence in urine of large amounts of glucose, and polyuria, the excretion of large volumes of urine. Additional symptoms arise in chronic or long standing diabetes. These symptoms include degeneration of the walls of blood vessels. Although many different organs are affected by these vascular changes, the eyes and kidneys appear to be the most susceptible. As such, long-standing diabetes mellitus, even when treated with insulin, is a leading cause of blindness.

There are two recognized types of diabetes. Type I diabetes is of juvenile onset, ketosis-prone, develops early in life with much more severe symptoms and has a near-certain prospect of later vascular involvement. Control of this type of diabetes is difficult and requires exogenous insulin administration. Type II diabetes mellitus is of adult onset, ketosis-resistant, develops later in life, is milder and has a more gradual onset.

One of the most significant advancements in the history of medical science came in 1922 when Batting and Best demonstrated the therapeutic effects of insulin in diabetic humans. However, even today, a clear picture of the basic biochemical defects of the disease is not known, and diabetes is still a serious health problem. It is believed that two percent of the United States' population is afflicted with some form of diabetes.

The introduction of orally effective hypoglycemic agents was an important development in the treatment of hyperglycemia by lowering blood glucose levels. Oral hypoglycemic agents are normally used in the treatment of adult onset diabetes.

A variety of biguanide and sulfonylurea derivatives have been used clinically as hypoglycemic agents. However, the biguanides tend to cause lactic acidosis and the sulfonylureas, though having good hypoglycemic activity, require great care during use because they frequently cause serious hypoglycemia and are most effective over a period of ten years.

In Chemical & Pharmaceutical Bulletin, 30, 3563 (1982), Chemical & Pharmaceutical Bulletin, 30, 3580 (1982) and Chemical & Pharmaceutical Bulletin, 32, 2267 (1984), reference is made to a variety of thiazolidinediones which have blood glucose and lipid lowering activities. Antidiabetic activity of ciglitazone was also reported in Diabetes, 32, 804 (1983). However, these compounds have proven difficult to use because of insufficient activities and/or serious toxicity problems.

The present invention relates to a series of hypoglycemic agents which are capable of lowering blood glucose levels in mammals. Accordingly, one object of the present invention is to provide compounds having excellent hypoglycemic activity. The hypoglycemic agents of the present invention are believed to have minimal toxicological effects. It is, therefore, believed that the compounds of the present invention may be very useful for treating diabetes. Other objects, features and advantages of the present invention will become apparent from the subsequent description and the appended claims.

SUMMARY OF THE INVENTION

The present invention provides a method of reducing blood glucose concentrations in mammals comprising administering a therapeutically effective amount of a compound of formula (I) ##STR1## wherein: Ar is (i) phenyl, (ii) phenyl substituted with from one to three substituents independently selected from C₁ -C₈ alkyl, C₁ -C₈ alkoxy, C₁ -C₈ alkylthio, trifluoromethyl, C₁ -C₄ alkylphenyl, phenyl, NO₂, F, Cl, hydroxy, phenoxy, C₁ -C₄ alkyloxyphenyl, thiophenyl, C₁ -C₄ alkylthiophenyl, --COOR⁷, --N(R⁷)SO₂ R⁷ or --N(R⁷)₂, where each R⁷ is independently hydrogen or C₁ -C₆ alkyl, (iii) 1- or 2-naphthyl, (iv) 2- or 3-benzofuranyl, (v) 2- or 3-benzothiophenyl, (vi) 2-, or 3-thienyl, (vii) 2-, 3- or 4-pyridyl, (viii) 2- or 3-furanyl, (ix) 1,3-benzodioxanyl, (x) substituted 1,3-benzodioxanyl, (xi) quinolinyl, (xii) 2- or 3-indolyl or (xiii) N-substituted 2- or 3-indolyl;

R¹ is C₁ -C₆ alkyl, C₁ -C₄ alkylphenyl, hydrogen, phenyl or phenyl substituted with one or two substituents independently selected from Cl, Br, F, I, C₁ -C₄ alkyl, C₁ -C₄ alkoxy, hydroxy, trifluoromethyl, --NH₂, --NH(C₁ -C₄ alkyl), --N(C₁ -C₄ alkyl)₂ or C₁ -C₄ alkylthio;

R² and R³ are each hydrogen or when taken together form a bond;

R⁴ and R⁵ are each hydrogen or when taken together are =S, or when one of R⁴ and R⁵ is hydrogen, the other is --SCH₃ ;

R⁶ is hydrogen, C₁ -C₆ alkyl, C₃ -C₈ cycloalkyl, C₂ -C₆ alkenyl, --SO₂ CH₃, or --(CH₂)_(p) --Y where p is 0, 1, 2, or 3 and Y is cyano, --OR⁸, ##STR2## tetrazolyl, --NR₁₀ R¹¹, --SH, C₁ -C₄ alkylthio, or ##STR3## where R⁸ is hydrogen, C₁ -C₄ alkyl or ##STR4## alkyl, R⁹ is hydrogen, C₁ -C₄ alkyl, C₁ -C₄ alkoxy, hydroxy or NH₂, and R¹⁰ and R¹¹ are each independently hydrogen, C₁ -C₆ alkyl, C₂ -C₆ alkenyl, C₂ -C₆ alkynyl, phenyl, C₁ -C₄ alkylphenyl, --(CH₂)_(q) OH, --(CH₂)_(q) N(C₁ -C₄ alkyl)₂, or --(CH₂)_(q) S(C₁ -C₄ alkyl),

where q is an integer from 1 to 6, both inclusive, or R¹⁰ and R¹¹, taken together with the nitrogen atom to which they are attached, form a morpholinyl, piperidinyl, piperizinyl, or N-methylpiperazinyl ring; and

m is 0, 1, or 2;

with the provisos that

Ar cannot be phenyl substituted solely with one chloro substituent at the 4-position of the phenyl ring;

Ar cannot be phenyl substituted with a COOH moiety at the 2-position of the phenyl ring;

when Ar is phenyl substituted with two ethoxy moieties at the 3- and 4-positions of the phenyl ring, R¹ must be hydrogen;

Ar cannot be phenyl substituted solely with two hydroxy substituents; and

when R⁴ and R⁵ are each hydrogen, R⁶ cannot be C₁ -C₆ alkyl,

or a pharmaceutically acceptable salt thereof, to a mammal in need of having its blood glucose concentration reduced.

Certain of the compounds which can be employed in the method of the present invention are novel. As such, the present invention also provides novel compounds of the formula (II) ##STR5## wherein: Ar is (i) phenyl, (ii) phenyl substituted with from one to three substituents independently selected from C₁ -C₈ alkyl, C₁ -C₈ alkoxy, C₁ -C₈ alkylthio, trifluoromethyl, C₂ -C₄ alkylphenyl, NO₂, F, Cl, phenoxy, C₁ -C₄ alkyloxyphenyl, thiophenyl, C₁ -C₄ alkylthiophenyl, --COOR⁷, --N(R⁷)SO₂ ^(R) ⁷ or --N(R⁷)₂, where each R⁷ is independently hydrogen or C₁ -C₆ alkyl, (iii) 1- or 2-naphthyl, (iv) 2- or 3-benzofuranyl, (v) 2- or 3-benzothiophenyl, (vi) 2- or 3-thienyl, (vii) 2-, 3- or 4-pyridyl, (viii) 2- or 3-furanyl, (ix) 1,3-benzodioxanyl, (x) substituted 1,3-benzodioxanyl, (xi) quinolinyl, (xii) 2- or 3-indolyl or (xiii) N-substituted 2- or 3-indolyl;

R¹ is C₁ -C₆ alkyl, C₁ -C₄ alkylphenyl, hydrogen, phenyl or phenyl substituted with one or two substituents independently selected from Cl, Br, F, I, C₁ -C₄ alkyl, C₁ -C₄ alkoxy, hydroxy, trifluoromethyl, --NH₂, --NH (C₁ -C₄ alkyl), --N(C₁ -C₄ alkyl)₂ or C₁ -C₄ alkylthio;

R² and R³ are each hydrogen or when taken together form a bond;

R⁴ and R⁵ are each hydrogen or when taken together are ═S, or when one of R⁴ and R⁵ is hydrogen, the other is --SCH₃ ;

R⁶ is hydrogen, C₁ -C₆ alkyl, C₃ -C₈ cycloalkyl, C₂ -C₆ alkenyl, --SO₂ CH₃ or --(CH₂)_(p) --Y where p is 0, 1, 2, or 3 and Y is cyano, OR⁸, ##STR6## tetrazolyl, --NR¹⁰ R¹¹, --SH, C₁ -C₄ alkylthio or ##STR7## where R⁸ is hydrogen, C₁ -C₄ alkyl, or ##STR8## alkyl; R⁹ is hydrogen, C₁ -C₄ alkyl or NH₂ ; and R¹⁰ and R¹¹ are each independently hydrogen, C₁ -C₆ alkyl, C₂ -C₆ alkenyl, --(CH₂)_(q) OH, --(CH₂)_(q) N(C₁ -C₄ alkyl)₂, --(CH₂)_(q) S(C₁ -C₄ alkyl), C₂ -C₆ alkynyl, phenyl, or C₁ -C₄ alkylphenyl, where q is 1 to 6, both inclusive, or R¹⁰ and R¹¹, taken together with the nitrogen atom to which they are attached, form a morpholinyl, piperidinyl, piperazinyl or N-methylpiperazinyl ring; and

m is 0, 1, or 2;

with the provisos that

when Ar is (i) phenyl, (ii) phenyl substituted with from one to three substituents selected from C₁ -C₈ alkyl, C₁ -C₈ alkoxy, F, Cl, trifluoromethyl, phenoxy, C_(1-C) ₄ alkyloxyphenyl, C₁ -C₈ alkylthio, NO₂, --N(R⁷)₂ or --COOR⁷, where each R⁷ is independently hydrogen or C₁ -C₆ alkyl, (iii) 1- or 2-naphthyl, (iv) 2- or 3-benzofuranyl, (v) 2- or 3-benzothiophenyl, (vi) 2- or 3-thienyl, (vii) 2- or 3-indolyl, (viii) 2- or 3-furanyl, (ix) quinolinyl or (x) 2-, 3- or 4-pyridyl; R¹ is hydrogen or C₁ -C₆ alkyl; R² and R³ taken together form a bond; m is 0; and R⁴ and R⁵ taken together are ═S, R⁶ must be other than hydrogen or C₁ -C₆ alkyl;

when Ar is phenyl; R¹ is hydrogen, methyl or ethyl; R² and R³ taken together form a bond; m is 0; R⁴ and R⁵ taken together are ═S; R⁶ must be other than phenyl or C₁ -C₄ alkylphenyl;

Ar cannot be phenyl substituted solely with one chloro substituent at the 4-position of the phenyl ring;

when Ar is phenyl substituted with two ethoxy moieties at the 3- and 4-positions of the phenyl ring, R¹ must be hydrogen;

Ar cannot be phenyl substituted with a COOH moiety at the 2-position of the phenyl ring; and

when R⁴ and R⁵ are each hydrogen R⁶ cannot be C₁ -C₆ alkyl,

and the pharmaceutically acceptable salts thereof.

In addition to the genus of novel compounds described by formula II, above, certain other of the compounds which can be employed in the method of the present invention also appear to be novel. These compounds, while structurally similar to compounds specifically known in the art (see, for example, European Patent Application Nos. 343643, 391644 and 39817 as well as U.S. Pat. No. 4,552,891 , are not actually described in any of those patents or applications. As such, the present invention also encompasses the following novel compounds and their pharmaceutically acceptable salts:

5-[(2-nitrophenyl)methylene]-2-thioxo-4-thiazolidinone;

5-[(4-fluorophenyl)methylene]-2-thioxo-4-thiazolidinone;

5-[(2-thienyl)methylene]-2-thioxo-4-thiazolidinone;

5-[(2-furanyl)methylene]-2-thioxo-4-thiazolidinone;

5-[(3,4,5-trimethoxyphenyl)methylmethylene]-2-thioxo-4-thiazolidinone;

4-[(2-thioxo-4-thiazolidinone)methylene]benzoic acid;

5-[(3-hydroxy-4-nitrophenyl)methylene]-2-thioxo-4-thiazolidinone;

5-[(3-hydroxyphenyl)methylmethylene]-2-thioxo--thiazolidinone;

5-[(3-methoxy-4-pentoxyphenyl)methylene]-2-thioxo-4-thiazolidinone;

5-[(3-hydroxy-4-ethoxyphenyl)methylene]-2-thioxo-4-thiazolidinone;

5-[(4-pentoxyphenyl)methylene]-2-thioxo-4-thiazolidinone;

5-[(3-ethoxy-4-propoxyphenyl)methylene]-2-thioxo-4-thiazolidinone;

5-[(3-propoxy-4-ethoxyphenyl)methylene]-2-thioxo-4-thiazolidinone;

5-[(3,4-dipropoxyphenyl)methylene]-2-thioxo-4-thiazolidinone;

5-[[3,5-bis(1,1-dimethylethyl)-4-hydroxy-phenyl]methylene]-4-oxo-2-thioxo-3-thiazolidine acetic acid;

5-[(3,5-dichloro-4-hydroxyphenyl)methylene]-2-thioxo-4-thiazolidinone;

5-[(3-ethoxy-4-butoxyphenyl)methylene]-2-thioxo-4-thiazolidinone;

5-[(3-ethoxy-4-methoxyphenyl)methylene ]-2-thioxo-4-thiazolidinone;

5-[[3,5-bis (1-methylpropyl)hydroxyphenyl]methylene]-4-oxo-2-thioxo-3-thiazolidine acetic acid;

5-[(4-butoxyphenyl)methylene]-2-thioxo-4-thiazolidinone;

5-[(3-methoxy-4-pentoxyphenyl)methylene]-2-thioxo-3-methyl-4-thiazolidinone;

5-[(3-methoxy-4-octoxyphenyl)methylene ]-2-thioxo-4-thiazolidinone;

5-[(3,5-dimethoxy-4-pentoxyphenyl)methylene]-2-thioxo-4-thiazolidinone;

5-[[3-(1,1-dimethylethyl)-4-hydroxy-5-(methylthiophenyl)phenyl]methylene]-2-thioxo-4-thiazolidinone;

5-[[3-ethoxy-4-hydroxy-5-(methylthiophenyl)phenyl]methylene]-2-thioxo-4-thiazolidinone;

5-[[3-ethoxy-4-hydroxy-5-(methylthiophenyl)phenyl]methylene]-2-thioxo-3-methyl-4-thiazolidinone;

5-[[3-ethoxy-4-hydroxy-5-(methylthiotphenyl)phenyl]methylene]-4-oxo-2-thioxo-3-thiazolidine acetic acid.

Certain of the above compounds and, in particular, 5-[(4-pentoxyphenyl)methylene]-2-thioxo-4-thiazolidinone; 5-[(3-propoxy-4-ethoxyphenyl)methylene]-2-thioxo-4-thiazolidinone; 5-[(3-ethoxy-4-butoxyphenyl)methylene]-2-thioxo-4-thiazolidinone; 5-[(4-butoxyphenyl)methylene]-2-thioxo-4-thiazolidinone; 5-[(3-methoxy-4-pentoxyphenyl)methylene]-2-thioxo-4-thiazolidinone; 5-[(3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methylene]-4-oxo-2-thioxo-3-thiazolidine acetic acid; and 5-[[3,5-bis(1-methylpropyl)-4-hydroxyphenyl]methylene]-4-oxo-2-thioxo-3-thiazolidine acetic acid (especially the latter three compounds), appear to possess a surprising ability to lower blood glucose levels in mammals compared to structurally similar compounds known in the art. Because of such surprising activity, these compounds are particularly preferred compounds of the present invention.

Finally, the present invention also provides pharmaceutical formulations comprising a compound of the present invention, or a pharmaceutically acceptable salt thereof, in combination with a pharmaceutically. acceptable carrier, diluent or excipient therefor.

DETAILED DESCRIPTION OF THE INVENTION

As used herein, the term "C₁ -C₈ alkyl" represents a straight or branched alkyl chain having from one to eight carbon atoms. Typical C₁ -C₈ alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, t-butyl, n-pentyl, and the like. The term "C₁ -C₈ alkyl" includes within its definition the terms "C₁ -C₄ alkyl" and "C₁ -C₆ alkyl".

"C₁ -C₄ alkylphenyl" represents a straight or branched chain alkyl group having from one to four carbon atoms attached to a phenyl ring. Typical C₁ -C₄ alkylphenyl groups include methylphenyl, ethylphenyl, n-propylphenyl, isopropylphenyl, n-butylphenyl, isobutylphenyl, and tert-butylphenyl.

The term "C₁ -C₄ alkylthiophenyl" represents a straight or branched chain alkyl group having from one to four carbon atoms attached to a thiophenyl moiety. Typical C₁ -C₄ alkylthiophenyl groups include methylthiophenyl, ethylthiophenyl, isobutylthiophenyl and the like.

In a similar fashion, the term "C₁ -C₄ alkyloxyphenyl" represents a straight or branched chain alkyl group having from one to four carbon atoms attached to phenoxy moiety. Typical C₁ -C₄ alkyloxyphenyl groups include methyloxyphenyl, ethyloxyphenyl, propyloxyphenyl and the like.

"C₁ -C₈ alkoxy" represents a straight or branched alkyl chain having one to eight carbon atoms, which chain is attached to the remainder of the molecule by an oxygen atom. Typical C₁ -C₈ alkoxy groups include methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, sec-butoxy, tert-butoxy, pentoxy, hexoxy, heptoxy, and the like. The term "C₁ -C₈ alkoxy" includes within its definition the term "C₁ -C₄ alkoxy".

"C₁ -C₈ alkylthio" represents a straight or branched alkyl chain having one to eight carbon atoms, which chain is attached to the remainder of the molecule by a sulfur atom. Typical C₁ -C₈ alkylthio groups include methylthio, ethylthio, propylthio, butylthio, tert-butylthio, octylthio and the like. The term "C₁ -C₈ alkylthio" includes within its definition the term "C₁ -C₄ alkylthio".

The term "C₂ -C₆ alkenyl" refers to straight and branched chain radicals of two to six carbon atoms, both inclusive, having a double bond. As such, the term includes ethylene, propylene, 1-butene, 2-butene, 2-methyl-1-propene, 1-pentene, 2-methyl-2-butene and the like.

The term "C₂ -C₆ alkynyl" refers to straight and branched chain radicals of two to six carbon atoms, both inclusive, having a triple bond. As such, the term includes acetylene, propyne, 1-butyne, 2-hexyne, 1-pentyne, 3-ethyl-1-butyne and the like.

The term "C₃ -C₈ cycloalkyl" refers to saturated alicyclic rings of three to eight carbon atoms, both inclusive, such as cyclopropyl, methylcyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclooctyl and the like.

The terms "1,3-benzodioxanyl" and "substituted 1,3-benzodioxanyl" refer to structures of the formulae ##STR9## where each R is independently hydrogen or C₁ -C₄ alkyl.

"Quinolinyl" refers to a quinoline ring system which is attached to the rest of the molecule at the 4, 5, 6, 7 or 8 position of such ring system.

"N-substituted 2- or 3-indolyl" refers to a 2- or 3-indolyl ring system substituted on the nitrogen atom of that ring system with a C₁ -C₆ alkyl, C₁ -C₄ alkylphenyl, or C₃ -C₈ cycloalkyl group.

The term "pharmaceutically acceptable salts" refers to salts of the compounds of the above formulae which are substantially non-toxic to living organisms. Typical pharmaceutically acceptable salts include those salts prepared by reaction of the compounds of the above formulae with a pharmaceutically acceptable mineral or organic acid, or a pharmaceutically acceptable alkali metal or organic base, depending on the types of substituents present on the compounds of the formulae.

Examples of pharmaceutically acceptable mineral acids which may be used to prepare pharmaceutically acceptable salts include hydrochloric acid, phosphoric acid, sulfuric acid, hydrobromic acid, hydroiodic acid, phosphorous acid and the like. Examples of pharmaceutically acceptable organic acids which may be used to prepare pharmaceutically acceptable salts include aliphatic mono and dicarboxylic acids, oxalic acid, carbonic acid, citric acid, succinic acid, phenyl-substituted alkanoic acids, aliphatic and aromatic sulfonic acids and the like. Such pharmaceutically acceptable salts prepared from mineral or organic acids thus include hydrochloride, hydrobromide, nitrate, sulfate, pyrosulfate, bisulfate, sulfite, bisulfite, phosphate, monohydrogenphosphate, dihydrogenphosphate, metaphosphate, pyrophosphate, hydroiodide, hydrofluoride, acetate, propionate, formate, oxalate, citrate, lactate, p-toluenesulfonate, methanesulfonate, maleate, and the like.

Many compounds of formula I or II which contain a carboxy, carbonyl, hydroxy or sulfoxide group may be converted to a pharmaceutically acceptable salt by reaction with a pharmaceutically acceptable alkali metal or organic base. Examples of pharmaceutically acceptable organic bases which may be used to prepare pharmaceutically acceptable salts include ammonia, amines such as triethanolamine, triethylamine, ethylamine, and the like. Examples of pharmaceutically acceptable alkali metal bases included compounds of the general formula MOR¹³, where M represents an alkali metal atom, e.g. sodium, potassium, or lithium, and R¹³ represents hydrogen or C₁ -C₄ alkyl.

It should be recognized that the particular anion or cation forming a part of any salt of this invention is not critical, so long as the salt, as a whole, is pharmacologically acceptable and as long as the anion or cationic moiety does not contribute undesired qualities.

A preferred genus of compounds useful in the instantly claimed method of reducing blood glucose concentrations includes those compounds wherein Ar, R¹, R², R³, m, R⁴, and R⁵ are as set forth for formula I, and R⁶ is hydrogen, C₁ -C₆ alkyl, C₃ -C₈ cycloalkyl, C₂ -C₆ alkenyl, --SO₂ CH₃ or --(CH₂)_(p) --Y where p is 0, 1, 2, or 3 and Y is cyano, --OR⁸, ##STR10## tetrazolyl, NR¹⁰ R¹¹, --SH, --S(C₁ -C₄ alkyl), or ##STR11## where R⁸ is hydrogen, C₁ -C₄ alkyl, or ##STR12## alkyl, R⁹ is hydrogen, C₁ -C₄ alkyl, or NH₂ ; and R¹⁰ and R¹¹ are each independently hydrogen, C₁ -C₆ alkyl, C₂ -C₆ alkenyl, C₂ -C₆ alkynyl, phenyl, C₁ -C₄ alkylphenyl, --(CH₂)_(q) OH, --(CH₂)_(q) N (C₁ -C₄ alkyl)₂, or --(CH₂ )_(q) S(C₁ -C₄ alkyl) where q is 1 to 6, both inclusive, or R¹⁰ and R¹¹, taken together with the nitrogen atom to which they are attached, form a morpholinyl, piperidinyl, piperazinyl, or N-methylpiperazinyl ring

Of this preferred genus, those compounds in which m is 0 are more preferred.

Of this more preferred genus, those compounds in which R⁴ and R⁵ taken together are ═S are even more preferred.

Of this even more preferred genus, those compounds in which R¹ is hydrogen are especially preferred.

Of this especially preferred genus, those compounds in which R⁶ is hydrogen, C₁ -C₆ alkyl, C₂ -C₆ alkenyl, or --(CH₂)_(p) --Y where p is 0, 1, 2, or 3 and Y is --OR⁸, ##STR13## --NR⁹, --NR¹⁰ R¹¹, or C₁ -C₄ alkylthio, where R⁸ is hydrogen, C₁ -C₄ alkyl or ##STR14## alkyl, R⁹ is hydrogen, C₁ -C₄ alkyl or NH₂ ; and R¹⁰ and R¹¹ are each independently hydrogen, C₁ -C₆ alkyl, C₂ -C₆ alkenyl, C₂ -C₆ alkynyl, phenyl, or C₁ -C₄ alkylphenyl are particularly preferred.

Of this particularly preferred genus, those compounds in which R⁶ is hydrogen, C₁ -C₆ alkyl, or C₂ -C₆ alkenyl are more particularly preferred.

Of this more particularly preferred genus, those compounds in which Ar is (i) phenyl, (ii) phenyl substituted with from one to three substituents independently selected from C₁ -C₈ alkyl, C₁ -C₈ alkoxy, C₁ -C₈ alkylthio, trifluoromethyl, C₁ -C₄ alkylphenyl, phenyl, NO₂, F, Cl, hydroxy, phenoxy, C₁ -C₄ alkyloxyphenyl, thiophenyl, C₁ -C₄ alkylthiophenyl, --COOR⁷, --N(R⁷)SO₂ R⁷ or --N(R⁷)₂, where each R⁷ is independently hydrogen or C₁ -C₆ alkyl, (iii) 2-, 3- or 4-pyridyl, or (iv) 2- or 3-furanyl are substantially preferred.

Of this substantially preferred genus, those compounds wherein Ar is phenyl substituted with from one to three substituents independently selected from C₁ -C₈ alkyl, C₁ -C₈ alkoxy, C₁ -C₄ alkylphenyl, phenyl, NO₂, F, Cl, hydroxy, phenoxy, C₁ -C₄ alkylthiophenyl, --COOR⁷ or --N(R⁷)SO₂ R⁷, where each R⁷ is independently hydrogen or C₁ -C₆ alkyl, are more substantially preferred.

Of this more substantially preferred genus, those compounds wherein Ar is phenyl substituted with from one to three substituents independently selected from C₁ -C₈ alkyl (especially C₁ -C₄ alkyl), C₁ -C₈ alkoxy (especially C₁ -C₆ alkoxy), or hydroxy are even more substantially preferred.

The most preferred compounds which may be employed in the method of the present invention include 5-[(3,4-diethoxyphenyl)methylene]-2-thioxo-4-thiazolidinone; 5-[(3-methoxy-4-butoxyphenyl)methylene]-2-thioxo-4-thiazolidinone; 5-[(3-methoxy-4-pentoxyphenyl)methylene]-2-thioxo-4-thiazolidinone; 5-[(3-methoxy-4-pentoxyphenyl)methylene]-2-thioxo-4-thiazolidinone, sodium salt; 5-[(3-methoxy-4-pentoxyphenyl)methyl]-2-thioxo-4-thiazolidinone; 5[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methylene]-2-thioxo-4-thiazolidinone; 5[(3,5-dimethyl-4-hydroxyphenyl)methylene]-2-thioxo-4-thiazolidinone and 5-[(3,5-dimethoxy-4-hydroxyphenyl)methylene]-2-thioxo-4-thiazolidinone.

A preferred genus of compounds of the present invention includes those compounds wherein Ar, R¹, R², R³, R⁴, R⁵ and R⁶ are as set forth for Formula II, and m is 0. Of this preferred genus, those compounds in which R⁴ and R⁵ taken together are ═S are more preferred. Of this more preferred genus, those compounds in which R² and R³ taken together form a bond are especially preferred.

Of this especially preferred genus, those. compounds in which R⁶ is hydrogen, C₁ -C₆ alkyl, C₂ -C₆ alkenyl, or --(CH₂)_(p) --Y where p is 0, 1, 2, or 3 and Y is --OR⁸, ##STR15## --NR¹⁰ R¹¹, or C₁ -C₄ alkylthio, where R⁸ is hydrogen, C₁ -C₄ alkyl or ##STR16## alkyl, R⁹ is hydrogen, C₁ -C₄ alkyl or NH₂ ; and R¹⁰ and R¹¹ are each independently hydrogen, C₁ -C₆ alkyl, C₂ -C₆ alkenyl, C₂ -C₆ alkynyl, phenyl, or C₁ -C₄ alkylphenyl are particularly preferred.

Of this particularly preferred genus, those compounds in which R⁶ is hydrogen, C₁ -C₆ alkyl, or C₂ -C₆ alkenyl are more particularly preferred. Of this more particularly preferred genus, those compounds in which R¹ is hydrogen or phenyl are even more particularly preferred.

Of this even more particularly preferred genus, those compounds in which Ar is (i) phenyl, (ii) phenyl substituted with from one to three substituents independently selected from C₁ -C₈ alkyl, C₁ -C₈ alkoxy, C₁ -C₈ alkylthio, trifluoromethyl, C₂ -C₄ alkylphenyl, NO₂, F, Cl, phenoxy, C₁ -C₄ alkoxyphenyl, thiophenyl, C₁ -C₄ alkylthiophenyl, --COOR⁷, --N(R⁷)SO₂ R⁷ or --N(R⁷)₂, where each R⁷ is independently hydrogen or C₁ -C₆ alkyl, (iii) 1,3-benzodioxanyl,(iv) substituted 1,3-benzodioxanyl or (v) quinolinyl are substantially preferred compounds.

Of this substantially preferred genus, those compounds wherein Ar is (i) phenyl substituted with from one to three of phenoxy or --N(R⁷)SO₂ R⁷, where each R⁷ is hydrogen or C₁ -C₆ alkyl or (ii) 1,3-benzodioxanyl are more substantially preferred.

Certain preferred compounds of the present invention include 5-(diphenylmethylene)-2-thioxo-4-thiazolidinone; 5-[(1,3-benzodioxol-5-yl)methylene)-2-thioxo-4-thiazolidinone; 5-[(4-phenoxyphenyl)methylene]-2-thioxo-4-thiazolidinone; and 5[(3-methanesulfonamidophenyl)methylene]-2-thioxo-4-thiazolidinone.

An alternative preferred genus of compounds of the present invention includes those compounds wherein Ar, R¹, R², R³, R⁴, R⁵, and m are as defined for formula II, and R⁶ is C₃ -C₈ cycloalkyl, C₂ -C₆ alkenyl, --SO₂ CH₃ or --(CH₂)_(p) --Y where p is 0, 1, 2, or 3 and Y is cyano, --OR⁸, ##STR17## tetrazolyl, --NR₁₀ R¹¹, --SH, C₁ -C₄ alkylthio, or ##STR18## where R⁸ is hydrogen, C₁ -C₄ alkyl, or ##STR19## alkyl; R⁹ is hydrogen, C₁ -C₄ alkyl, or NH₂ ; and R.sup. 10 and R¹¹ are each independently hydrogen, C₁ -C₆ alkyl, C₂ -C₆ alkenyl, C₂ -C₆ alkynyl, phenyl, C₁ -C₄ alkylphenyl, --(CH₂)_(q) OH, --(CH₂)_(q) N(C₁ -C₄ alkyl)₂, or --(CH₂)_(q) S(C₁ -C₄ alkyl) where q is 1 to 6, both inclusive, or R.sup. 10 and R¹¹, taken together with the nitrogen atom to which they are attached, form a morpholinyl, piperidinyl, piperazinyl, or N-methylpiperazinyl ring.

Of this preferred genus, those compounds in which m is 0 are more preferred.

Of this more preferred genus, those compounds in which R⁴ and R⁵ taken together are =S are even more preferred.

Of this even more preferred genus, those compounds in which R² and R³ taken together form a bond are especially preferred

Of this especially preferred genus, those compounds in which R⁶ is C₂ -C₆ alkenyl, or --(CH₂)_(p) --Y where p is 0, 1, 2, or 3 and Y is --OR⁸, ##STR20## --NR¹⁰ R¹¹, or C₁ -C₄ alkylthio, where R⁸ is hydrogen, C₁ -C₄ alkyl or ##STR21## alkyl R⁹ is hydrogen, C₁ -C₄ alkyl or NH₂ ; and R¹⁰ and R¹¹ are each independently hydrogen, C₁ -C₆ alkyl, C₂ -C₆ alkenyl, C₂ -C₆ alkynyl, phenyl, or C₁ -C₄ alkylphenyl are particularly preferred.

Of this particularly preferred genus, those compounds wherein R¹ is hydrogen or phenyl are more particularly preferred.

Of this more particularly preferred genus, those compounds in which Ar is (i) phenyl, (ii) phenyl substituted with from one to three substituents independently selected from C₁ -C₈ alkyl, C₁ -C₈ alkoxy, C₁ -C₈ alkylthio, trifluoromethyl, C₂ -C₄ alkylphenyl, NO₂, F, Cl, phenoxy, C₁ -C₄ alkoxyphenyl, thiophenyl, C₁ -C₄ alkylthiophenyl, --COOR⁷, --N(R⁷)SO₂ R⁷ or --N(R⁷)₂, where each R⁷ is independently hydrogen or C₁ -C₆ alkyl (iii) 2-, 3- or 4-pyridyl, or (iv) 2- or 3-furanyl are even more particularly preferred.

Of this even more particularly preferred genus, those compounds wherein Ar is phenyl substituted with from one to three substituents independently selected from C₁ -C₈ alkyl, C₁ -C₈ alkoxy, C₁ -C₈ alkylthio, trifluoromethyl, C₂ -C₄ alkylphenyl, NO₂, F, Cl, phenoxy, C₁ -C₄ alkoxyphenyl, thiophenyl, C₁ -C₄ alkylthiophenyl, --COOR⁷, --N(R⁷)SO₂ R⁷ or --N(R⁷)₂, where each R⁷ is independently hydrogen or C₁ -C₆ alkyl, are substantially preferred.

Of this substantially preferred genus, those compounds wherein Ar is phenyl substituted with from one to three substituents independently selected from C₁ -C₈ alkyl or C₁ -C₈ alkoxy are most preferred.

The present invention also encompasses formulations comprising a compound of the present invention in combination with a pharmaceutically acceptable carrier, diluent, or excipient therefor. Preferred formulations of the present invention are those formulations which contain a preferred compound or genus of compounds of the present invention, as described above.

The following examples illustrate the preparation of the compounds of this invention. The examples are illustrative only and are not intended to limit the scope of the invention in any way.

The compounds of the present invention, as well as the compounds employed in the method of the present invention, can, typically, be prepared by methods well known to one skilled in the art of organic chemistry. For example, such compounds may be prepared by condensation of rhodanine, or an appropriately substituted rhodanine derivative, with an appropriately substituted aromatic aldehyde or aldehyde derivative such as a mono or disubstituted imine of the formula ##STR22## or ##STR23## Such reaction is illustrated utilizing an appropriately substituted aromatic aldehyde as follows ##STR24## where Ar and R⁶ are as defined in formulae I and II.

Compounds of the present invention (as well as those compounds employed in the method of the present invention) wherein R² and R³ are hydrogen, or when taken together form a bond, and R⁴ and R⁵ are each hydrogen can be prepared by subjecting the compound wherein R⁴ and R⁵ taken together form ═S to catalytic hydrogenation. The relative proportions of compound obtained (R², R³, R⁴ and R⁵ all hydrogen vs. R² and R³ taken together form a bond and R⁴ and R⁵ are hydrogen) depends upon the temperature, pressure, and duration of hydrogenation, the solvent employed and the particular catalyst used. Alternatively, the above transformations may be accomplished by heating the compounds wherein R⁴ and R⁵ taken together are ═S and R² and R³ taken together are a double bond in a mixture of hydrochloric acid and an alcohol, such as ethanol, in the presence of zinc. Reduction of the thione without affecting the benzylic double bond may be accomplished by heating the thione with a reducing agent such as tri-n-butyl tin hydride in a non-reactive solvent, such as toluene, and preferably in the presence of a free radical initiator, such as azobisisobutyronitrile. However, for such reduction to work, an N-substituted rhodanine substrate must be employed.

The transformation of compounds wherein R² and R³. taken together form a bond and R⁴ and R⁵ taken together are ═S to those compounds wherein R² and R³ are both hydrogen while R⁴ and R⁵ remain unchanged may be accomplished by treating the unsaturated compound with a dihydropyridine, such as diethyl 2,6-dimethyl-1,4-dihydro-3,5-pyridine dicarboxylate in the presence of silica gel. The reaction is best carried out in the presence of a nonreactive solvent such as benzene or toluene, preferably under an inert atmosphere. The reaction may be accomplished at temperatures from about 25° C. up to the reflux temperature of the mixture. At the preferred temperature of approximately 80° C., the reaction is essentially complete after about 12-18 hours.

Compounds of formulae I or II wherein R¹ is C₁ -C₆ alkyl, phenyl, a substituted phenyl of the type described above, or C₁ -C₄ alkylphenyl may be prepared by conventional Friedel-Crafts acylation of an appropriately substituted aromatic compound with an acyl halide of the formula R¹ --C(O)--X, wherein R¹ is as defined in formulae I or II and X is chloro, fluoro, bromo or iodo. The resulting aromatic ketone is then condensed with rhodanine, or an appropriately substituted rhodanine derivative.

The compounds of the present invention (as well as the compounds employed in the method of the present invention) allow various R⁶ substituents. These R⁶ substituents can be prepared as follows.

Compounds of formulae I and II wherein R⁶ is hydrogen, C₁ -C₆ alkyl, C₃ -C₈ cycloalkyl or --(CH₂)_(p) --Y where p is as defined for formulae I and II and Y is cyano, or NR¹⁰ R¹¹ where R¹⁰ and R¹¹ are each independently hydrogen or C₁ -C₆ alkyl may be prepared using the method set forth in the above reaction scheme. Alternatively, rhodanine may be used for condensation with an aldehyde or aldehyde derivative forming those species wherein R⁶ is hydrogen, followed by alkylation or acylation with the appropriate R⁶ -containing halide. The alkylation or acylation is usually accomplished in an inert solvent such as tetrahydrofuran or dimethylformamide and in the presence of a strong base such as sodium hydride.

Alternatively, compounds of formulae I and II wherein R⁶ is --(CH₂)_(p) --Y where Y is cyano may be prepared by treating the non-cyanated analog with a halo-substituted aliphatic nitrile. From this cyano derivative the tetrazolyl is prepared as by treatment with tri-N-butyl tin azide in, for example, ethylene glycol dimethyl ether.

Compounds of formulae I and II wherein R⁶ is --(CH₂)_(p) --Y (p=0) and Y is NR¹⁰ R¹¹, where R¹⁰ and R¹¹ are as defined in formulae I and II, may also be prepared by employing an appropriately substituted hydrazine. In this reaction sequence, benzaldehyde is reacted with an appropriately substitued hydrazine, in an alcoholic solvent, yielding III. An appropriately substituted alkyl halide is then reacted with III, in the presence of triethylamine and acetonitrile, to provide IV, which is then further reacted with hydrazine to yield the R¹⁰, R¹¹ hydrazine V. Compound V may alternatively be prepared by the reduction of a nitroso-R¹⁰ R¹¹ amine using zinc dust and acetic acid or aluminum and a strong base. The R¹⁰, R¹¹ hydrazine is then treated with carbon disulfide, chloroacetic acid and triethylamine to provide intermediate VI. Condensation of VI with an appropriately substituted aromatic aldehyde or aldehyde derivative yields the desired product, as represented by the following reaction scheme. ##STR25##

Furthermore, the thione portion of the compound produced above may be reduced by treatment with a reducing agent such as tri-n-butyltin hydride in an inert solvent such as toluene, preferably in the presence of a free radical initiator such as azobisisobutyronitrile. Preparation of compounds wherein one of R¹⁰ and R¹¹ is hydrogen may be effected before or after reduction of the thione, as desired, by heating the disubstituted compound in a mixture of ethanol/water in the presence of a catalyst such as a rhodium catalyst.

Compounds of formulae I and II wherein R⁶ is --(CH₂)_(p) --Y and Y is OR⁸ or NR¹⁰ R¹¹ (where R⁸ is hydrogen, acetyl or tosyl and R¹⁰ and R¹¹ are each independently hydrogen or C₁ -C₆ alkyl) may also be prepared according to the following reaction scheme: ##STR26##

A hydroxyalkyl rhodanine is prepared by condensing carbon disulfide, chloroacetic acid, and the appropriate hydroxyalkylamine by standard techniques. When condensed with the appropriately substituted aromatic aldehyde (or aldehyde derivative), as described above, the resulting product is the condensed 2-thioxo-4-thiazolidinone VIII which has been transformed into the acetyl derivative. The thioxo compound VIII may optionally be converted to the methylene compound of formulae I or II as described above. The acetyl group of intermediate IX may be removed upon treatment with aqueous ammonia in a solvent such as acetonitrile to provide Compound X. The hydroxy compound X is then converted to the tosyl derivative upon treatment with p-toluenesulfonyl chloride in pyridine, preferably at temperatures of around 0° C. The versatile tosyl intermediate XI may then be transformed into the compounds of formulae I or II upon treatment with an appropriate HNR¹⁰ R¹¹ amine. This latter transformation is best accomplished by allowing XI to react in the presence of a molar excess of the amine. Once again, a solvent such as acetonitrile is useful for accomplishing this transformation.

Those compounds where m is 1 or 2 are readily prepared from the sulfide (m=0) by treatment with an oxidizing agent, such as m-chloroperbenzoic acid, in a suitable solvent for a time sufficient to generate the desired oxidative state.

Depending upon the definitions of R¹, R², and R³, the compounds of formulae I and II may exist in various isomeric forms. The compounds, formulations and methods of the present invention are not related to any particular isomer but include all possible isomers and racemates.

It will be readily appreciated by one skilled in the art that the aromatic portion of the compounds of the invention (or the compounds employed in the method of the present invention) can be provided by compounds which are either commercially available or may be readily prepared by known techniques from commercially available starting materials. Similarly, the rhodanine or N-substituted rhodanine starting material is either commercially available or may be prepared by well known methods from commercially available substrates.

The following Examples illustrate the preparation of the compounds of the present invention, as well as compounds which may be employed in the method of the present invention. The Examples are illustrative only and are not intended to limit the scope of the instant invention in any way.

EXAMPLE 1

5-[(3-methanesulfonamidophenyl)methylene]-2-thioxo-4-thiazolidinone

Thirty seven grams (185.9 mmol) of 3-methanesulfonamidbenzaldehyde, 25.0 g (187.9 mmol) of rhodanine, 48.0 g (585.3 mmol) of anhydrous sodium acetate and 950 ml of acetic acid were stirred while heating at reflux for 20 hours. The reaction was then stirred at room temperature for approximately another 60 hours. The resulting slurry was poured into 3000 ml of a 1:1 ethanol/water mixture. Solids precipitated and were recovered by filtration, washed with water and then vacuum dried to provide 54 g of title compound. m.p. 260°-265° C.

Analysis for C₁₁ H₁₀ N₂ O₃ S₃ Calculated: C, 42.02; H, 3.20; N 8.91; Found: C, 42.15; H, 3.57; N 8.71.

EXAMPLE 2 5-[(1,3-benzodioxol-5-yl)methylene]-2-thioxo-4-thiazolidinone

Twenty grams (133.2 mmol) of piperonal were reacted with 17.74 g (133.2 mmol)of rhodanine in 38.24 g (466.2 mmol) of glacial acetic acid at reflux for about 3 hours. The mixture was then poured into water and stirred overnight. A precipitate formed which was recovered by filtration and then air dried overnight to provide 27.8 g of title product. m.p. 194°-195° C. Analysis for C₁₁ H₇ N₁ O₃ S₂ : Calculated: C, 49.80; H, 2.66; N 5.28; S, 24.17; Found: C, 50.04; H, 2.38; N 5.27; S, 23.98.

EXAMPLE 3 5-[(4-quinolinyl)methylene]-2-thioxo-4-thiazolidinone

Rhodanine (2.2 g; 16.5 mmol), 1.3 ml of concentrated ammonium hydroxide and 1 g of ammonium chloride in 20 ml of ethanol were heated on a steam bath for 15 minutes. 4-Quinoline carboxaldehyde (2.6 g; 16.5 mmol) was added and the resulting mixture was heated on the steam bath for another hour. Upon cooling to 5° C. a precipitate formed. This precipitate was recovered by filtration and then washed with water to provide 4 g of title compound, m.p. 325°-328° C.

Analysis for C₁₃ H₈ N₂ OS₂ : Calculated: C, 57.33; H, 2.96; N 10.29; Found: C, 57.11; H, 3.11; N 10.21.

EXAMPLE 4 5-(diphenylmethylene)-2-thioxo-4-thiazolidinone

One hundred and ninety grams (1.05 mol) of diphenyl ketimine, 140 grams (1.05 mol) of rhodanine, 5 ml of acetic acid and 1500 ml of toluene were heated at reflux for 3 hours. Crystals formed upon cooling. The solvent was decanted, fresh toluene was added to the residue and the resulting suspension was filtered. The recovered crystals were recrystallized from methanol to provide 172.0 g of title product, m.p. 192°-194° C.

Analysis for C₁₆ H₁₁ NOS₂ : Calculated: C, 64.62; H, 3.73; 0, 5.38; N 4.71; S, 21.56; Found: C, 64.13; H, 3.84; 0, 5.57; N 4.59; S, 22.38.

EXAMPLE 5 5-[(4-phenoxyphenyl)methylene]-2-thioxo-4-thiazolidinone

A mixture of 9.9 g (50.0 mmol) of 4-phenoxybenzaldehyde, 6.8 g (51.1 mmol) of rhodanine, 15.5 g of sodium acetate and 60 ml of acetic acid was heated on a steam bath for two hours. The reaction solution was then poured into water causing crude product to precipitate. The precipitate was filtered and then washed successively with water followed by diethyl ether to provide 8.6 g of title product, m.p. 195°-200° C.

Analysis for C₁₆ H₁₁ NO₂ S₂ : Calculated: C, 61.32; H, 3.54; N 4.47; Found: C, 61.07; H, 3.63; N 4.47.

The following compounds were synthesized using methods substantially equivalent to those described in Examples 1-5 above or as described elsewhere herein.

EXAMPLE 6 5-(phenylmethylene)-2-thioxo-4-thiazolidinone, m.p. 202°-203.5° C. EXAMPLE 7 5-[(2-hydroxyphenyl)methylene]-2-thioxo-4-thiazolidinone, m.p. 220°-222° C. EXAMPLE 8 5-[(4-hydroxyphenyl)methylene]-2-thioxo-4-thiazolidinone, m.p. 287°-290° C. EXAMPLE 9 5-[(2-nitrophenyl)methylene]-2-thioxo-4-thiazolidinone, m.p. 197.5°-199° C. EXAMPLE 10 5-[(3-nitrophenyl)methylene]-2-thioxo-4-thiazolidinone, m.p. 277°-280° C. EXAMPLE 11 5-[(3-hydroxyphenyl)methylene ]-2-thioxo-4-thiazolidinone, m.p. 242°-244° C. EXAMPLE 12 5-[(2,4-dimethoxyphenyl)methylene ]-2-thioxo-4-thiazolidinone, m.p. 253°-255° C. EXAMPLE 13 5-[(4-fluorophenyl)methylene]-2-thioxo-4-thiazolidinone, m.p. 225°-227° C. EXAMPLE 14 5-[(2-thienyl)methylene]-2-thioxo-4-thiazolidinone, m.p. 231°-233° C. EXAMPLE 15 5-[(2-furanyl)methylene]-2-thioxo-4-thiazolidinone, m.p. 217°-219° C. EXAMPLE 16 5-[(4-pyridyl)methylene]-2-thioxo-4-thiazolidinone, m.p. 297°-298° C. EXAMPLE 17 5-[(3,4,5-trimethoxyphenyl)methylene]-2-thioxo-4-thiazolidinone, m.p. 203°-205° C. EXAMPLE 18 5-[(4-methoxyphenyl)methylene]-2-thioxo-4-thiazolidinone, m.p. 252°-254° C. EXAMPLE 19 5-[(3,4,5-trimethoxyphenyl)methylmethylene]-2-thioxo-4-thiazolidinone, m.p. 210°-213° C. EXAMPLE 20 5-[(3-methoxy-4-hydroxyphenyl)methylene]-2-thioxo-4-thiazolidinone, m.p. 229°-231° C. EXAMPLE 21 5-[(4-methoxyphenyl)phenylmethylene]-2-thioxo-4-thiazolidinone, m.p. 169°-171° C. EXAMPLE 22 5-[(3-pyridyl)methylene]-2-thioxo-4-thiazolidinone, m.p. ˜286° C. EXAMPLE 23 5-[(3-chlorophenyl)methylene]-2-thioxo-4-thiazolidinone, m.p. 233°-235° C. EXAMPLE 24 5-[(2,3-dimethoxyphenyl)methylene]-2-thioxo-4-thiazolidinone EXAMPLE 25 5-[(3-methoxyphenyl)methylene]-2-thioxo-4-thiazolidinone EXAMPLE 26 5-[(2-methoxyphenyl)methylene]-2-thioxo-4-thiazolidinone EXAMPLE 27 5-[(3-methyl-4-methoxyphenyl)methylene]-2-thioxo-4-thiazolidinone EXAMPLE 28 5-[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methylene]-2-thioxo-4-thiazolidinone, ˜260° C. EXAMPLE 29 5-[(1,1'-biphenyl]-2-yl)methylene)-2-thioxo-4-thiazolidinone EXAMPLE 30 5-[(3-methoxy-4-hydroxyphenyl)methylene ]-3-(2-propenyl)-2-thioxo-4-thiazolidinone, m.p. 146°-148° C. EXAMPLE 31 5-[(3-methoxy-4-heptoxyphenyl)methylene]-2-thioxo-4-thiazolidinone, m.p. 130°-132° C. EXAMPLE 32 5-[(3-ethoxy-4-hydroxyphenyl)methylene]-2-thioxo-4-thiazolidinone, m.p. 217°-217.5° C. EXAMPLE 33 5-[(3-methylphenyl)methylene]-2-thioxo-4-thiazolidinone, m.p. 197°-202° C. EXAMPLE 34 5-[(4-methylphenyl)methylene]-2-thioxo-4-thiazolidinone, m.p. 229°-234° C. EXAMPLE 35 5-[(2-naphthalenyl)methylene)-2-thioxo-4-thiazolidinone, m.p. 224°-225° C. EXAMPLE 36 5-[(3,4-dichlorophenyl)methylene]-2-thioxo-4-thiazolidinone EXAMPLE 37 4-[(2-thioxo-4-thiazolidinone)methylene]benzoic acid, m.p. ˜320° C. EXAMPLE 38 5-[(3,4-diethoxyphenyl)methylene]-2-thioxo-4-thiazolidinone EXAMPLE 39 5-[(1H-indol-3-yl)methylene]-2-thioxo-4-thiazolidinone EXAMPLE 40 5-[(3-hydroxy-4-methoxyphenyl)methylene]-2-thioxo-4-thiazolidinone, m.p. 218°-220° C. EXAMPLE 41 5-[(3-methoxy-4-butoxyphenyl)methylene]-2-thioxo-4-thiazolidinone, m.p. 175°-176° C. EXAMPLE 42 5-[(1,1'-biphenyl ]-4-yl)methylene ]-2-thioxo-4-thiazolidinone, m.p. 245°-250° C. EXAMPLE 43 5-[(3-hydroxy-4-nitrophenyl)methylene]-2-thioxo-4-thiazolidinone, m.p. ˜224° C. EXAMPLE 44 5-[(3-hydroxyphenyl)methylmethylene]-2-thioxo-4-thiazolidinone EXAMPLE 45 5-[(3-methoxy-4-pentoxyphenyl)methylene ]-2-thioxo-4-thiazolidinone, m.p. 170°-171° C. EXAMPLE 46 5-[(3-hydroxy-4-ethoxyphenyl)methylene]-2-thioxo-4-thiazolidinone, m.p. >225° C. EXAMPLE 47 5-[(4-pentoxyphenyl)methylene]-2-thioxo-4-thiazolidinone, m.p. 158.5°-160° C. EXAMPLE 48 5-[(3-methoxy-4-ethoxyphenyl)methylene]-2-thioxo-4-thiazolidinone, m.p. 207°-207.5° C. EXAMPLE 49 5-[(3-ethoxy-4-propoxyphenyl)methylene]-2-thioxo-4-thiazolidinone, m.p. 156°-157° C. EXAMPLE 50 5-[(3-propoxy-4-ethoxyphenyl)methylene]-2-thioxo-4-thiazolidinone, m.p. 186.5°-188° C. EXAMPLE 51 5-[(3,4-dipropoxyphenyl)methylene]-2-thioxo-4-thiazolidinone, m.p. 167.5°-168.5° C. EXAMPLE 52 5-[(3-methoxy-4-butoxyphenyl)methylene]-2-thioxo-4-thiazolidinone, sodium salt m.p. >225° C. EXAMPLE 53 5-[[3,5-bis(1,1-dimethylethyl)-4-hydroxy-phenyl]methylene]-4-oxo-2-thioxo-3-thiazolidine acetic acid, m.p. ˜265° C. EXAMPLE 54 5-[(3-methoxy-4-butoxyphenyl)methyl]-2-thioxo-4-thiazolidinone, m.p. 152°-153.5° C. EXAMPLE 55 5-[(3,5-dichloro-4-hydroxyphenyl)methylene]-2-thioxo-4-thiazolidinone, m.p. >260° C. EXAMPLE 56 5-[(3-ethoxy-4-butoxyphenyl)methylene]-2-thioxo-4-thiazolidinone EXAMPLE 57 5-[(3-methoxy-4-pentoxyphenyl)methylene]-2-thioxo-4-thiazolidinone sodium salt, m.p. ˜254° C. EXAMPLE 58 5-[(3-ethoxy)-4-methoxyphenyl)methylene]-2-thioxo-4-thiazolidinone, m.p. >225° C. EXAMPLE 59 5-[[3,5-bis(1-methylpropyl)-4-hydroxyphenyl]methylene]-4-oxo-2-thioxo-3-thiazolidine acetic acid, m.p. 191°-193° C. EXAMPLE 60 5-[(3,4-dimethoxyphenyl)methylene]-2-thioxo-4-thiazolidinone EXAMPLE 61 5-[(4-butoxyphenyl)methylene]-2-thioxo-4-thiazolidinone, m.p. 180° C. EXAMPLE 62 5-[(3,5-dimethyl-4-hydroxyphenyl)methylene]-2-thioxo-4-thiazolidinone, m.p. 260° C. EXAMPLE 63 5-[(3,5-dimethoxy-4-hydroxyphenyl)methylene]-2-thioxo-4-thiazolidinone, m.p. 230° C. EXAMPLE 64 5-[(3-methoxy-4-pentoxyphenyl)methyl]-2-thioxo-4-thiazolidinone, m.p. 163°-164° C. EXAMPLE 65 5-[(3-methoxy-4-pentoxyphenyl)methylene]-2-thioxo-3-methyl-4-thiazolidinone, m.p. 117°-118° C. EXAMPLE 66 5-[(3-methoxy-4-pentoxyphenyl)methylene]-4-thiazolidinone, m.p. 174°-175° C. EXAMPLE 67 5-[(3-methoxy-4-pentoxyphenyl)methyl]-4-thiazolidinone, m.p. 108°-109° C. EXAMPLE 68 5-[(3-methoxy-4-hexoxyphenyl)methylene]-2-thioxo-4-thiazolidinone EXAMPLE 69 5-[(3-methoxy-4-octoxyphenyl)methylene]-2-thioxo-4-thiazolidinone, m.p. 125°-127° C. EXAMPLE 70 5-[(3,5-dimethoxy-4-pentoxyphenyl)methylene]-2-thioxo-4-thiazolidinone, m.p. 166°-167° C. EXAMPLE 71

5-[[3-(1,1-dimethylethyl)-4-hydroxy-5-(methylthiophenyl)phenyl]methylene]-2-thioxo-4-thiazolidinone, m.p. 181°-184° C.

EXAMPLE 72 5-[[3-ethoxy-4-hydroxy-5-(methylthio-phenyl)phenyl]methylene]-2-thioxo-4-thiazolidinone, m.p. 190°-192° C. EXAMPLE 73 5-[[3-ethoxy-4-hydroxy-5-(methylthiophenyl)phenyl]methylene]-2-thioxo-3-methyl-4-thiazolidinone, m.p. 137° C. EXAMPLE 74 5-[[3-ethoxy-4-hydroxy-5-(methylthiophenyl)phenyl]methylene]-4-oxo-2-thioxo-3-thiazolidine acetic acid m.p. 202°-206° C.

The present invention provides a method for lowering blood glucose levels in mammals comprising administering a therapeutically effective amount of a compound of formula I. The term "therapeutically effective amount", as defined herein, means the amount of compound necessary to provide a hypoglycemic effect following administration, preferably to a human susceptible to adult onset diabetes.

The hypoglycemic activity of the compounds of the present invention was determined by testing the efficacy of the compounds in vivo in male viable yellow obese-diabetic mice. The test procedure is described in detail below.

Test formulations were prepared by dissolving the test compound in a saline solution containing 2% Emulphor (a polyoxyethylated vegetable oil surfactant from GAF Corp.) to provide the dose level desired. Each test formulation was administered to six viable yellow obese-diabetic mice intraperitoneally at the beginning of the experiment. Blood glucose levels Were determined immediately before the first dose and at 2 and 4 hours thereafter using glucose oxidase. A mean was taken of the 6 values obtained before the first dose and at the 2 and 4 hour intervals. The 2 and 4 hour mean values, calculated as a percentage of the first dose mean value, are reported in Table 1, below. In Table 1, Column 1 provides the example number of the test compound, Column 2 provides the dose level of compound tested, and Columns 3 and 4 provide a measurement of the test animal's blood glucose level 2 and 4 hours after test compound administration, respectively, as a percentage of the test animal's pre-administration blood glucose level.

                  TABLE 1                                                          ______________________________________                                         HYPOGLYCEMIC ACTIVITY OF TEST COMPOUNDS IN                                     OBESE DIABETIC MICE                                                                             Percent of Initial                                            Example # of           Blood Glucose Level                                     Compound   Dose        After    After                                          Tested     (mg/kg)     2 hrs.   4 hrs.                                         ______________________________________                                          1         50          82 ± 5                                                                               75 ± 2                                       2         50          96 ± 1                                                                               82 ± 3                                       3         50           90 ± 10                                                                             73 ± 3                                       4         50          91 ± 4                                                                               72 ± 7                                       5         50          79 ± 4                                                                               71 ± 3                                       6         50          85 ± 6                                                                               72 ± 4                                       6         50          92 ± 4                                                                               79 ± 4                                       7         50          80 ± 4                                                                               91 ± 7                                       8         50          94 ± 4                                                                               84 ± 6                                       9         50          91 ± 8                                                                               83 ± 6                                      10         50          89 ± 4                                                                               80 ± 4                                      11         50          84 ± 3                                                                               85 ± 6                                      12         50          90 ± 7                                                                               69 ± 6                                      13         50          94 ± 4                                                                               88 ± 5                                      14         50          84 ± 7                                                                               71 ± 8                                      15         50          73 ± 5                                                                               62 ± 4                                      16         50          94 ± 8                                                                               96 ± 9                                      17         50          88 ± 8                                                                                89 ± 10                                    18         50          89 ± 4                                                                               88 ± 5                                      19         50           85 ± 14                                                                             75 ± 4                                      20         50          76 ± 3                                                                               70 ± 5                                      21         50          99 ± 4                                                                               81 ± 6                                      22         50          77 ± 5                                                                               67 ± 2                                      22         50          77 ± 6                                                                               69 ± 6                                      23         50          74 ± 6                                                                               90 ± 6                                      24         50          78 ± 4                                                                               80 ± 5                                      25         50          78 ± 4                                                                               74 ± 4                                      25         25          84 ± 5                                                                               87 ± 6                                      26         50          80 ± 4                                                                               75 ± 2                                      27         50          93 ± 3                                                                               84 ± 6                                      28         50          83 ± 9                                                                               79 ± 7                                      29         50          84 ± 5                                                                               77 ± 6                                      30         50          78 ± 7                                                                               81 ± 5                                      31         50          76 ± 7                                                                               76 ± 5                                      32         50          75 ± 4                                                                               80 ± 8                                      32         50           80 ± 18                                                                              66 ± 11                                    33         50          91 ± 6                                                                               86 ± 7                                      34         50          85 ± 8                                                                               79 ± 9                                      35         50          83 ± 5                                                                               85 ± 6                                      36         50          81 ± 7                                                                               90 ± 8                                      37         50          89 ± 4                                                                               80 ± 4                                      38         50          60 ± 5                                                                               59 ± 4                                      38         50          96 ± 6                                                                               80 ± 3                                      38         50          86 ± 4                                                                               81 ± 5                                      38         25          69 ± 9                                                                               65 ± 7                                      38         10          72 ± 4                                                                               71 ± 6                                      38         10          73 ± 8                                                                               59 ± 7                                      39         50          83 ± 4                                                                               76 ± 4                                      40         50          78 ± 5                                                                               72 ± 4                                      41         50          61 ± 3                                                                               51 ± 4                                      41         50          64 ± 6                                                                               54 ± 5                                      41         50          77 ± 5                                                                               62 ± 5                                      41         50          77 ± 5                                                                               72 ± 8                                      41         25          58 ± 6                                                                               45 ± 5                                      41         25          72 ± 7                                                                               64 ± 4                                      41         25          74 ± 7                                                                               70 ± 8                                      41         25          87 ± 5                                                                               85 ± 6                                      41         10          80 ± 7                                                                               59 ± 4                                      41         10          97 ± 7                                                                               75 ± 5                                      41         10          92 ± 7                                                                               92 ± 7                                      41          5           93 ± 10                                                                             71 ± 4                                      41          5          95 ± 4                                                                               97 ± 5                                      42         50          87 ± 8                                                                               70 ± 8                                      43         50          92 ± 7                                                                               88 ± 4                                      44         50          98 ± 4                                                                               88 ± 5                                      45         50          76 ± 7                                                                               57 ± 3                                      45         50          68 ± 2                                                                               66 ± 4                                      45         25          93 ± 4                                                                               87 ± 5                                      45         25           83 ± 10                                                                              78 ± 12                                    46         50          79 ± 4                                                                               77 ± 5                                      47         50           99 ± 14                                                                             76 ± 8                                      48         50          70 ± 3                                                                               65 ± 3                                      48         25          87 ± 4                                                                               81 ± 5                                      49         50          83 ± 5                                                                               77 ± 7                                      50         50          75 ± 5                                                                               69 ± 5                                      51         50          89 ± 7                                                                               85 ± 8                                      52         50          73 ± 3                                                                               61 ± 4                                      53         100         83 ± 9                                                                                80 ± 14                                    53         50          73 ± 4                                                                               55 ± 5                                      54         50          76 ± 7                                                                               74 ± 6                                      55         50          81 ± 3                                                                               75 ± 3                                      56         50          78 ± 4                                                                               72 ± 3                                      56         25          81 ± 8                                                                               75 ± 3                                      56         10          94 ± 4                                                                               97 ± 4                                      57         50          63 ± 6                                                                               58 ± 7                                      57         50          69 ± 5                                                                               63 ± 7                                      57         25          67 ± 7                                                                               66 ± 7                                      57         25           79 ± 10                                                                             70 ± 4                                      57         10          95 ± 3                                                                               87 ± 6                                      57          5          82 ± 6                                                                               68 ± 5                                      58         50          67 ± 2                                                                               75 ± 5                                      59         50          62 ± 5                                                                               59 ± 9                                      60         50          85 ± 4                                                                               78 ± 3                                      60         50          102 ± 6                                                                              81 ± 5                                      60         25          87 ± 7                                                                               89 ± 6                                      61         50          76 ± 5                                                                               61 ± 5                                      61         50          98 ± 8                                                                               79 ± 4                                      ______________________________________                                    

The hypoglycemic activity of the compounds of the present invention was confirmed in a second in vivo test system; namely, the normal fed rat system. The procedure used in this test system is described below.

Male Sprague Dawley rats (Charles River Laboratories) weighing 175°-200 g were used in this test system. Test formulations were prepared by suspending the test compound in 5% acacia (concentration of the drug was adjusted such that 0.25 ml/100 g body weight administered orally gave the desired dose on a body weight basis). The desired dose level of each test formulation was administered to four rats by oral garage at the beginning of the experiment. Blood glucose levels were determined immediately before the first dose and at 3 and 5 hours thereafter by an enzymatic procedure employing glucose oxidase and peroxidase coupled with a chromogenic oxygen acceptor. A mean was taken of the 4 values obtained before the first dose and at the 3 and 5 hour intervals. The 3 and 5 hour mean values, calculated as a percentage of the first dose mean value, are reported in Table 2, below. In Table 2, Column 1 provides the example number of the test compound, Column 2 provides the dose level of compound tested, and Columns 3 and 4 provide a measurement of the test animal's blood glucose level 3 and 5 hours after test compound administration, respectively, as a percentage of the test animal's pre-administration blood glucose level.

                  TABLE 2                                                          ______________________________________                                         HYPOGLYCEMIC ACTIVITY OF TEST COMPOUNDS IN                                     NORMAL FED RATS                                                                                 Percent of Initial                                            Example # of           Blood Glucose Level                                     Compound   Dose        After    After                                          Tested     (mg/kg)     3 hrs.   5 hrs.                                         ______________________________________                                         15         167         84       87                                             16         200         92       79                                             17         200         78       68                                             22         200         84       68                                             24         200         100      100                                            25         200         100      100                                            26         200         100      100                                            31         200         95       92                                             32         200         100      96                                             38         200         90       74                                             41         160         76       67                                             45         167         61       63                                             47         200         82       73                                             48         167         87       81                                             49         200         100      98                                             56         150         79       65                                             57         200         84       73                                             58         200         100      100                                            61         200         89       82                                             62         200         78       53                                             63         200         69       52                                             64         200         91       89                                             65         200         100      91                                             66         200         100      86                                             67         200         92       88                                             68         200         88       89                                             69         200         93       88                                             ______________________________________                                    

The hypoglycemic activity of the compounds of the present invention was confirmed in yet a third in vivo test system; namely, the obese diabetic Zucker rat (Zucker Diabetic Fatty Rat) test system. The rats used in this test system were 6 to 8 months old, weighed between 550 to 625 grams and had a pre-drug blood glucose level between 250 to 350 mg/dl. The procedure used in this test system is the same as that described for the normal fed rat test system, above. The results of such tests are set forth in Table 3, below. The format of Table 3 is the same as that used in Table 2.

                  TABLE 3                                                          ______________________________________                                         HYPOGLYCEMIC ACTIVITY OF TEST COMPOUNDS IN                                     OBESE DIABETIC ZUCKER RATS                                                                      Percent of Initial                                            Example # of           Blood Glucose Level                                     Compound   Dose        After    After                                          Tested     (mg/kg)     3 hrs.   5 hrs.                                         ______________________________________                                         22          50         53       56                                             45         167         30       20                                             47         167         74       66                                             56          50         79       66                                             ______________________________________                                    

Finally, the long-term hypoglycemic activity of the compounds of the present invention was tested in yet another in vivo test system. This long-term test system entailed incorporating test compound into the test animal's diet at various concentrations (control animal's diet contained no test compound). Such diet was then fed to the test or control animals for either 14 or 21 days. Each test or control animal was then bled from the tail (200-400 μl sample of blood) at 0 (before diet started), 7, 14 and, if appropriate, 21 and 28 days after diet administration was started. Plasma samples were then obtained from each blood sample collected and the glucose concentration of such plasma samples was determined enzymatically.

The results of the long-termhypoglycemic test system described above are set forth in Table 4, below. In Table 4, Column 1 describes the type of rodents used in the test system, Column 2 provides the example number of the test compound or indicates that the numbers reported are for a control animal, Column 3 provides the concentration, in percent, of test compound in the test or control animal's diet. Columns 4-8 provide the plasma glucose concentration at days 0, 7, 14 and, if appropriate, 21 and 28, respectively, for the animals tested. Glucose lowering was not associated with depressed diet consumption.

                  TABLE 4                                                          ______________________________________                                         LONG-TERM HYPOGLYCEMIC ACTIVITY OF                                             TEST COMPOUNDS                                                                                  Concen-                                                               Example  tration                                                               No.      of Test  Plasma Glucose Concentration                         Type of of Cmpd. Cmpd. in (mg/dl)                                              Rodent* Tested   Diet (%) 0    7    14   21   28                               ______________________________________                                         ZDF     45       0.1      388  140  155  --   --                               ZDF     control  --       416  364  445  --   --                               ZDF     45       0.1      464  215  238  285  --                               ZDF     45       0.025    467  451  452  517  --                               ZDF     control  --       478  499  571  565  --                               ZDF     45       0.1      357  171  166  --   --                               ZDF     64       0.1      339  187  182  --   --                               ZDF     control  --       343  423  454  --   --                               ZDF     45       0.1      309  137  142  --   --                               ZDF     71       0.1      311  237  232  --   --                               ZDF     70       0.1      300  190  195  --   --                               ZDF     control  --       317  286  255  --   --                               Male A.sup.vy /a                                                                       45       0.1      438  338  315  287  295                              (Harlan)                                                                       Male A.sup.vy /a                                                                       38       0.1      340  351  328  303  331                              (Harlan)                                                                       Male A.sup.vy /a                                                                       control  --       429  414  410  390  359                              (Harlan)                                                                       ______________________________________                                          *ZDF = 8 week old male Zucker Diabetic Fatty rat; A.sup.vy /.sup.a =           viable yellow mouse                                                      

The compounds of the present invention and the compounds utilized in the method of the present invention are effective over a wide dosage range. For example, dosages per day will normally fall within the range of about 0.5 to about 500 mg/kg of body weight. In the treatment of adult humans, the range of about 1.0 to about 100 mg/kg, in single or divided doses, is preferred. However, it will be understood that the amount of the compound actually administered will be determined by a physician in light of the relevant circumstances including the condition to be treated, the choice of compound to be administered, the age, weight, and response of the individual patient, the severity of the patient's symptoms and the chosen route of administration. Therefore, the above dosage ranges are not intended to limit the scope of the invention in any way. While the present compounds are preferably administered orally, the compounds may also be administered by a variety of other routes such as the transdermal, subcutaneous, intranasal, intramuscular and intravenous routes.

While it is possible to administer a compound of the invention directly, the compounds are preferably employed in the form of a pharmaceutical formulation comprising a pharmaceutically acceptable carrier, diluent or excipient and a compound of the invention. Such formulations will contain from about 0.01 percent to about 90 percent of a compound of the invention.

In making the formulations of the present invention, the active ingredient will usually be mixed with at least one carrier, or diluted by at least one carrier, or enclosed within a carrier which may be in the form of a capsule, sachet, paper or other container. When the carrier serves as a diluent, it may be a solid, semi-solid or liquid material which acts as a vehicle, excipient or medium for the active ingredient. Thus, the formulations can be in the form of tablets, granules, pills, powders, lozenges, sachets, cachets, elixirs, emulsions, solutions, syrups, suspensions, aerosols (as a solid or in a liquid medium) and soft and hard gelatin capsules.

Examples of suitable carriers, diluents and excipients include lactose, dextrose, sucrose, sorbitol, mannitol, starches, gum acacia, calcium phosphate, alginates, liquid paraffin, calcium silicate, microcrystalline cellulose, polyvinyl pyrrolidone, cellulose, tragacanth, gelatin, syrup, methyl cellulose, methyl- and propyl-hydroxybenzoates, vegetable oils, such as olive oil, injectable organic esters such as ethyl oleate, talc, magnesium stearate, water and mineral oil. The formulations may also include wetting agents, lubricating, emulsifying and suspending agents, preserving agents, sweetening agents, perfuming agents, stabilizing agents or flavoring agents. The formulations of the invention may be formulated so as to provide quick,.sustained or delayed release of the active ingredient after administration to the patient by employing procedures well-known in the art.

For oral administration, a compound of this invention ideally can be admixed with carriers and diluents and molded into tablets or enclosed in gelatin capsules.

The compositions are preferably formulated in a unit dosage form, each dosage containing from about 1 to about 500 mg, more usually about 5 to about 300 mg, of the active ingredient. The term "unit dosage form" refers to physically discrete units suitable as unitary dosages for human subjects and other mammals, each unit containing a predetermined quantity of. active material calculated to produce the desired therapeutic effect, in association with a suitable pharmaceutical carrier, diluent or excipient therefor.

In order to more fully illustrate the operation of this invention, the following examples of formulations are provided. The examples are illustrative only and are not intended to limit the scope of the invention. The formulations may employ as active compounds any of the compounds of the present invention.

    ______________________________________                                         FORMULATION 1                                                                  Hard gelatin capsules are prepared using the                                   following ingredients:                                                                         Amt. per                                                                              Concentration by                                                        Capsule                                                                               Weight (percent)                                        ______________________________________                                         Compound of Example No. 5                                                                        250 mg   55.0                                                Starch dried      220 mg   43.0                                                Magnesium stearate                                                                                10 mg    2.0                                                                  460 mg   100.0                                               ______________________________________                                    

The above ingredients are mixed and filled into hard gelatin capsules in 460 mg quantities.

    ______________________________________                                         FORMULATION 2                                                                  Capsules each containing 20 mg of medicament are                               made as follows:                                                                               Amt. per                                                                              Concentration by                                                        Capsule                                                                               Weight (percent)                                        ______________________________________                                         Compound of Example No. 1                                                                        20 mg    10.0                                                Starch            89 mg    44.5                                                Microcrystalline  89 mg    44.5                                                cellulose                                                                      Magnesium stearate                                                                                2 mg     1.0                                                                  200 mg   100.0                                               ______________________________________                                    

The active ingredient, cellulose, starch and magnesium stearate are blended, passed through a No. 45 mesh U.S. sieve and filled into a hard gelatin capsule.

    ______________________________________                                         FORMULATION 3                                                                  Capsules each containing 100 mg of active                                      ingredient are made as follows:                                                               Amt. per Concentration by                                                      Capsule  Weight (percent)                                       ______________________________________                                         Compound of Example No. 45                                                                      100     mg     29.0                                           Polyoxyethylenesorbitan                                                                         50      mcg     0.02                                          monooleate                                                                     Starch powder    250     mg     71.0                                                            250.05  mg     100.02                                         ______________________________________                                    

The above ingredients are thoroughly mixed and placed in an empty gelatin capsule.

    ______________________________________                                         FORMULATION 4                                                                  Tablets each containing 10 mg of active                                        ingredient are made up as follows:                                                             Amt. per                                                                              Concentration by                                                        Capsule                                                                               Weight (percent)                                        ______________________________________                                         Compound of Example No. 3                                                                        10     mg    10.0                                            Starch            45     mg    45.0                                            Microcrystalline  35     mg    35.0                                            cellulose                                                                      Polyvinyl         4      mg    4.0                                             pyrrolidone (as 10%                                                            solution in water)                                                             Sodium carboxyethyl                                                                              4.5    mg    4.5                                             starch                                                                         Magnesium stearate                                                                               0.5    mg    0.5                                             Talc              1      mg    1.0                                                               100    mg    100.0                                           ______________________________________                                    

The active ingredient, starch and cellulose are passed through a No. 45 mesh U.S. sieve and mixed thoroughly. The solution of polyvinylpyrrolidone is mixed with the resultant powders which are then passed through a No. 14 mesh U.S. sieve. The granule so produced is dried at 50°-60° C. and passed through a No. 18 mesh U.S. sieve. The sodium carboxymethyl starch, magnesium stearate and talc, previously passed through a No. 60 mesh U.S. sieve, are then added to the granule which, after mixing, is compressed on a tablet machine to yield a tablet weighing 100 mg.

    ______________________________________                                         FORMULATION 5                                                                  A tablet formula may be prepared using the                                     ingredients below:                                                                             Amt. per                                                                              Concentration by                                                        Capsule                                                                               Weight (percent)                                        ______________________________________                                         Compound of Example No. 2                                                                        250 mg   38.0                                                Cellulose         400 mg   60.0                                                microcrystalline                                                               Silicon dioxide    10 mg    1.5                                                fumed                                                                          Stearic acid       5 mg     0.5                                                                  665 mg   100.0                                               ______________________________________                                    

The components are blended and compressed to form tablets each weighing 665 mg.

    ______________________________________                                         FORMULATION 6                                                                  Suspensions each containing 5 mg of medicament                                 per 40 ml dose are made as follows:                                                               Per 5 ml of suspension                                      ______________________________________                                         Compound of Example No. 59                                                                          5         mg                                              Sodium carboxymethyl 50        mg                                              cellulose                                                                      Syrup                1.25      ml                                              Benzoic acid solution                                                                               0.10      ml                                              Flavor               q.v.                                                      Color                q.v.                                                      Water                q.s. to 5 ml                                              ______________________________________                                    

The medicament is passed through a No. 45 mesh U.S. sieve and mixed with the sodium carboxymethylcellulose and syrup to form a smooth paste. The benzoic acid solution, flavor and color is diluted with some of the water and added, with stirring. Sufficient water is then added to produce the required volume.

    ______________________________________                                         FORMULATION 7                                                                  An aerosol solution is prepared containing the                                 following components:                                                                          Concentration by Weight (%)                                    ______________________________________                                         Compound of Example No. 53                                                                        0.25                                                        Ethanol           29.75                                                        Propellant 22     70.00                                                        (Chlorodifluoromethane)                                                                          100.00                                                       ______________________________________                                    

The active compound is mixed with ethanol and the mixture added to a portion of the propellant 22, cooled to -30° C. and transferred to a filling device. The required amount is then fed to a stainless steel container and diluted further with the remaining amount of propellant. The valve units are then fitted to the container. 

We claim:
 1. A method of reducing blood glucose concentrations in mammals which comprises administering a therapeutically effective amount of a compound of the formula ##STR27## wherein: Ar is (i) phenyl, (ii) phenyl substituted with from one to three substituents independently selected from C₁ -C₈ alkyl, C₁ -C₈ alkoxy, C₁ -C₈ alkylthio, trifluoromethyl, C₁ -C₄ alkylphenyl, phenyl, NO₂, F, Cl, hydroxy, phenoxy, C₁ -C₄ alkyloxyphenyl, thiophenyl, C₁ -C₄ alkylthiophenyl, --COOR⁷, --N(R⁷)₂ or --N(R⁷)SO₂ R⁷, where each R⁷ is independently hydrogen or C₁ -C₆ alkyl, (iii) 1- or 2-naphthyl, (iv) 2- or 3-benzofuranyl, (v) 2- or 3-benzothiophenyl, (vi) 2- or 3-thienyl, (vii) 2-, 3- or 4-pyridyl, (viii) 2- or 3-furanyl, (ix) 1,3-benzodioxanyl, (x) substituted 1,3-benzodioxanyl, (xi) quinolinyl, (xii) 2- or 3-indolyl or (xiii) N-substituted 2- or 3-indolyl;R¹ is C₁ -C₆ alkyl, C₁ -C₄ alkylphenyl, hydrogen, phenyl or phenyl substituted with one or two substituents independently selected from Cl, Br, F, I, C₁ -C₄ alkyl C₁ -C₄ alkoxy, hydroxy, trifluoromethyl, --NH₂, --NH(C₁ -C₄ alkyl), --N(C₁ -C₄ alkyl)₂ or C₁ -C₄ alkylthio; R² and R³ are each hydrogen or when taken together form a bond; R⁴ and R⁵ are each hydrogen or when taken together are ═S, or when one of R⁴ and R⁵ is hydrogen, the other is --SCH₃ ; R⁶ is hydrogen, C₁ -C₆ alkyl, C₃ -C₈ cycloalkyl, C₂ -C₆ alkenyl, --SO₂ CH₃, or --(CH₂)_(p) --Y where p is 0, 1, 2, or 3 and Y is cyano, --OR⁸, ##STR28## tetrazolyl, --NR¹⁰ R¹¹, --SH, C₁ -C₄ alkylthio, or ##STR29## where R⁸ is hydrogen, C₁ -C₄ alkyl, or ##STR30## alkyl; R⁹ is hydrogen, C₁ -C₄ alkyl, or NH₂ ; and R¹⁰ and R¹¹ are each independently hydrogen, C₁ -C₆ alkyl, C₂ -C₆ alkenyl, C₂ -C₆ alkynyl, phenyl, C₁ -C₄ alkylphenyl, --(CH₂)_(q) OH, --(CH₂)_(q) N(C₁ -C₄ alkyl)₂, or --(CH₂)_(q) S(C₁ -C₄ alkyl), where q is an integral from 1 to 6, both inclusive, or R¹⁰ and R¹¹, taken together with the nitrogen atom to which they are attached form a morpholinyl, piperidinyl, piperazinyl, or N-methylpiperazinyl ring; m is 0, 1, or 2;with the provisos that Ar cannot be phenyl substituted solely with one chloro substituent at the 4-position of the phenyl ring; Ar cannot be phenyl substituted with a COOH moiety at the 2-position of the phenyl ring; when Ar is phenyl substituted with two ethoxy moieties at the 3- and 4-positions of the phenyl ring, R¹ must be hydrogen; Ar cannot be phenyl substituted solely with two hydroxy substituents; and when R⁴ and R⁵ are each hydrogen, R⁶ cannot be C₁ -C₆ alkyl,or a pharmaceutically acceptable salt thereof, to a mammal in need of having its blood glucose concentration reduced.
 2. A method of claim 1 which employs a compound wherein m is
 0. 3. A method of claim 2 which employs a compound wherein R⁴ and R⁵ taken together are ═S.
 4. A method of claim 3 which employs a compound wherein R¹ is hydrogen.
 5. A method of claim 4 which employs a compound wherein R⁶ is hydrogen, C₁ -C₆ alkyl, C₂ -C₆ alkenyl, or --(CH₂)_(p) --Y where p is 0, 1, 2, or 3 and Y is --OR⁸, ##STR31## --NR¹⁰ R¹¹, or C₁ -C₄ alkylthio, where R⁸ is hydrogen, C₁ -C₄ alkyl or ##STR32## alkyl, R⁹ is hydrogen, C₁ -C₄ alkyl, or NH₂ ; and R¹⁰ and R¹¹ are each independently hydrogen, C₁ -C₆ alkyl, C₂ -C₆ alkenyl, C₂ -C₆ alkynyl, phenyl, or C₁ -C₄ alkylphenyl.
 6. A method of claim 5 which employs a compound wherein R⁶ is hydrogen, C₁ -C₆ alkyl, or C₂ -C₆ alkenyl.
 7. A method of claim 6 which employs a compound wherein Ar is (i) phenyl, (ii) phenyl substituted with from one to three substituents independently selected from C₁ -C₈ alkyl, C₁ -C₈ alkoxy, C₁ -C₈ alkylthio, trifluoromethyl, C₁ -C₄ alkylphenyl, phenyl, NO₂, F, Cl, hydroxy, phenoxy, C₁ -C₄ alkyloxyphenyl, thiophenyl, C₁ -C₄ alkylthiophenyl, --COOR⁷, --N(R⁷)SO₂ R⁷ or --N(R⁷)₂, where each R⁷ is independently hydrogen or C₁ -C₆ alkyl, (iii) 2-, 3- or 4-pyridyl, or (iv) 2- or 3-furanyl.
 8. A method of claim 7 which employs a compound wherein Ar is phenyl substituted with from one to three substituents independently selected from C₁ -C₈ alkyl, C₁ -C₈ alkoxy, or hydroxy.
 9. A method of claim 8 wherein the compound employed is 5-[(3,4-diethoxyphenyl)methylene]-2-thioxo-4-thiazolidinone or a pharmaceutically acceptable salt thereof.
 10. A method of claim 8 wherein the compound employed is 5-[(3-methoxy-4-butoxyphenyl)methylene]-2-thioxo-4-thiazolidinone or a pharmaceutically acceptable salt thereof.
 11. A method of claim 8 wherein the compound employed is 5-[(3-methoxy-4-pentoxyphenyl)methylene]-2-thioxo-4-thiazolidinone or a pharmaceutically acceptable salt thereof.
 12. A method of claim 8 wherein the compound employed is 5-[(3-methoxy-4-pentoxyphenyl)methyl]-2-thioxo-4-thiazolidinone or a pharmaceutically acceptable salt thereof.
 13. A method of claim 8 wherein the compound employed is 5-[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methylene]-2-thioxo-4-thiazolidinone or a pharmaceutically acceptable salt thereof.
 14. A method of claim 8 wherein the compound employed is 5-[(3,5-dimethyl-4-hydroxyphenyl)methylene]-2-thioxo-4-thiazolidinone or a pharmaceutically acceptable salt thereof.
 15. A method of claim 8 wherein the compound employed is 5-[(3,5-dimethoxy-4-hydroxyphenyl)methylene]-2-thioxo-4-thiazolidinone or a pharmaceutically acceptable salt thereof. 